Re: Tech question about exhaust? Axle back bolt to Cat back?
I have the Heartthrob 3" cat to axle kit, and had a local muffler shop install Flowmaster 40's. Prior to having the 40's installed, I just had the stock mufflers on and there were no fitment issues. The aftermarket kits are designed to bolt right up, so you should be fine. What typy of cat-back kit do you have? As long as it is designed to work with the stock mufflers, it will work with the major brands making axle-backs.
2016 Mustang GT